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Finding the Fourth Proportional to 280.90, 421.50 and 109.90

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Solution

The fourth proportional to 280.90, 421.50 and 109.90 is: 164.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.90 : 421.50 = 109.90 : x
  2. Step 2: Convert to fraction form
    280.90/421.50 = 109.90/x
  3. Step 3: Cross multiply
    280.90x = 421.50 × 109.90
  4. Step 4: Simplify right side
    280.90x = 46,322.85
  5. Step 5: Solve for x
    x = 46,322.85/280.90
  6. Step 6: Final answer
    x = 164.91

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.